import {
  DEFAULT_UPDATE_REMOTE,
  isOfficialRepoUrl,
  normalizeRepoUrl,
  normalizeUpdateBranch,
} from "./self-update.js";

/**
 * The GitHub repository whose CI fills the image namespace. `publish-server-image.yml` pushes to
 * `ghcr.io/${{ github.repository }}`, so the namespace always belongs to whichever repository ran
 * the workflow. Naming a different owner here points the deployment at packages nobody publishes.
 *
 * `OFFICIAL_REPO_URL` names the same repository, so the source commit selected from a release is
 * guaranteed to have been eligible for this repository's publishing workflow.
 */
export const PUBLISHED_IMAGE_REPO = "cynarai/evoo-local";

/** The published server image. One image runs api, worker, and web. */
export const OFFICIAL_SERVER_IMAGE = `ghcr.io/${PUBLISHED_IMAGE_REPO}/app`;
/** The updater sidecar's image, published alongside the server image but tagged independently. */
export const OFFICIAL_UPDATER_IMAGE = `ghcr.io/${PUBLISHED_IMAGE_REPO}/updater`;

/**
 * The tag a deployment that has never run an update is on. It is deliberately *not* `latest`: no
 * registry serves this tag, so `docker compose up --build` builds it from the checkout and a fresh
 * install works with an empty registry. `latest` only exists once a release has been published.
 */
export const LOCAL_IMAGE_TAG = "local";
export const DEFAULT_IMAGE_TAG = LOCAL_IMAGE_TAG;
export const IMAGE_TAG_ENV = "RAKAZO_IMAGE_TAG";
export const PREVIOUS_IMAGE_TAG_ENV = "RAKAZO_IMAGE_TAG_PREVIOUS";

/**
 * Matches the `name:` pinned in `infra/compose/docker-compose.prod.yml`. Used when Compose has not
 * injected `COMPOSE_PROJECT_NAME` (it does, into running services) and no dedicated override is set.
 */
export const DEFAULT_COMPOSE_PROJECT_NAME = "rakazo-prod";
export const COMPOSE_PROJECT_NAME_ENV = "COMPOSE_PROJECT_NAME";
export const COMPOSE_PROJECT_NAME_OVERRIDE_ENV = "RAKAZO_COMPOSE_PROJECT_NAME";

/**
 * The services a recreate replaces. `updater` is deliberately absent: it is the process running
 * the update, and recreating it would kill the run half way through. `postgres` and `caddy` are
 * absent because neither uses the Rakazo image.
 */
export const RECREATED_SERVICES = ["api", "worker", "web"] as const;

const IMAGE_TAG = /^[A-Za-z0-9_][A-Za-z0-9._-]{0,127}$/;
const IMAGE_NAME_SEGMENT = /^[a-z0-9]+(?:[._-][a-z0-9]+)*$/;
const IMAGE_HOST = /^[a-z0-9]+(?:[.-][a-z0-9]+)*(?::[0-9]{1,5})?$/;
const COMMIT = /^[0-9a-f]{40,64}$/;
const ENV_KEY = /^[A-Z][A-Z0-9_]*$/;
const ENV_VALUE = /^[A-Za-z0-9._:/@+-]{0,256}$/;
const RELEASE_TAG = /^v(\d+)\.(\d+)\.(\d+)(?:-([0-9A-Za-z.-]+))?$/;
/** Compose project names must not start with `-`, or `-p` would treat them as a second flag. */
const COMPOSE_PROJECT_NAME = /^[a-zA-Z0-9][a-zA-Z0-9_-]{0,63}$/;

export function isValidImageTag(tag: string): boolean {
  return IMAGE_TAG.test(tag);
}

/** A registry reference the updater is willing to hand to `docker compose` as one env value. */
export function isValidImageName(name: string): boolean {
  if (name.length === 0 || name.length > 200) return false;
  const segments = name.split("/");
  const first = segments[0] ?? "";
  const hasHost = segments.length > 1 && (first.includes(".") || first.includes(":"));
  if (hasHost && !IMAGE_HOST.test(first)) return false;
  return segments.slice(hasHost ? 1 : 0).every((segment) => IMAGE_NAME_SEGMENT.test(segment));
}

export function isValidComposeProjectName(name: string): boolean {
  return COMPOSE_PROJECT_NAME.test(name);
}

/**
 * The project `-p` must name. Compose injects `COMPOSE_PROJECT_NAME` into running services, which
 * is the stack the operator actually started (including `docker compose -p something-else`). A
 * dedicated override exists for running the sidecar outside Compose. Unset falls back to the name
 * pinned in the compose file, never to guessing from the working directory.
 */
export function resolveComposeProjectName(
  env: Readonly<Record<string, string | undefined>>,
): string {
  const injected = env[COMPOSE_PROJECT_NAME_ENV]?.trim() ?? "";
  const override = env[COMPOSE_PROJECT_NAME_OVERRIDE_ENV]?.trim() ?? "";
  const candidate = injected || override;
  if (candidate === "") return DEFAULT_COMPOSE_PROJECT_NAME;
  if (!isValidComposeProjectName(candidate)) {
    throw new Error(`Refusing an unusable Compose project name: ${candidate}`);
  }
  return candidate;
}

export function imageRef(name: string, tag: string): string {
  if (!isValidImageName(name)) throw new Error(`Refusing an unusable image name: ${name}`);
  if (!isValidImageTag(tag)) throw new Error(`Refusing an unusable image tag: ${tag}`);
  return `${name}:${tag}`;
}

/**
 * The tag a fork's build is stored under. Forks have no published images, so the tag has to be
 * local and distinguishable from anything the registry could serve, or a later `pull` of the same
 * name would silently replace the operator's own build.
 */
export function forkImageTag(commit: string): string {
  if (!COMMIT.test(commit)) throw new Error("A fork build needs a resolved commit to tag.");
  return `local-${commit}`;
}

/**
 * A tag that only exists on this host, so trying to pull it would fail rather than find nothing.
 * Covers both the per-commit fork builds (`local-<commit>`) and the bare `local` a fresh install
 * builds, because a rollback onto either has to skip `docker compose pull`.
 */
export function isLocalImageTag(tag: string): boolean {
  return tag === LOCAL_IMAGE_TAG || tag.startsWith(`${LOCAL_IMAGE_TAG}-`);
}

/**
 * The source-addressed per-commit tag the publish workflow pushes. This has to agree character for
 * character with `docker/metadata-action`'s `type=sha`. The workflow deliberately raises
 * `DOCKER_METADATA_SHORT_SHA_LENGTH` to 40 so source-addressed image tags cannot collide at the
 * action's unsafe seven-character default.
 */
export function commitImageTag(commit: string): string {
  if (!COMMIT.test(commit)) throw new Error("A commit tag needs a resolved commit.");
  return `sha-${commit}`;
}

export interface ReleaseTag {
  tag: string;
  major: number;
  minor: number;
  patch: number;
  prerelease: string | null;
}

export function parseReleaseTag(tag: string): ReleaseTag | null {
  const match = RELEASE_TAG.exec(tag);
  if (!match) return null;
  return {
    tag,
    major: Number(match[1]),
    minor: Number(match[2]),
    patch: Number(match[3]),
    prerelease: match[4] ?? null,
  };
}

export function compareReleaseTags(a: ReleaseTag, b: ReleaseTag): number {
  if (a.major !== b.major) return a.major - b.major;
  if (a.minor !== b.minor) return a.minor - b.minor;
  if (a.patch !== b.patch) return a.patch - b.patch;
  if (a.prerelease === b.prerelease) return 0;
  if (a.prerelease === null) return 1;
  if (b.prerelease === null) return -1;
  return a.prerelease < b.prerelease ? -1 : 1;
}

/** Reads `git ls-remote --tags <url>`, which is the tag list without cloning anything. */
export function parseLsRemoteTags(stdout: string): string[] {
  const tags = new Set<string>();
  for (const line of stdout.split("\n")) {
    const ref = line.split("\t")[1]?.trim();
    if (!ref?.startsWith("refs/tags/")) continue;
    const tag = ref.slice("refs/tags/".length).replace(/\^\{\}$/, "");
    if (tag !== "" && isValidImageTag(tag)) tags.add(tag);
  }
  return [...tags];
}

export interface RemoteRelease {
  tag: string;
  /** The commit behind the tag, never the object id of an annotated tag. */
  commit: string;
}

/**
 * Reads the source commit for each release. Annotated tags have two `ls-remote` rows; the peeled
 * `^{}` row wins so the image tag agrees with `github.sha` in the publishing workflow.
 */
export function parseLsRemoteReleases(stdout: string): RemoteRelease[] {
  const releases = new Map<string, { direct?: string; peeled?: string }>();
  for (const line of stdout.split("\n")) {
    const [commit = "", rawRef = ""] = line.trim().split(/\s+/, 2);
    if (!COMMIT.test(commit) || !rawRef.startsWith("refs/tags/")) continue;
    const peeled = rawRef.endsWith("^{}");
    const tag = rawRef.slice("refs/tags/".length).replace(/\^\{\}$/, "");
    if (tag === "" || !isValidImageTag(tag)) continue;
    const entry = releases.get(tag) ?? {};
    if (peeled) entry.peeled = commit;
    else entry.direct = commit;
    releases.set(tag, entry);
  }
  return [...releases].flatMap(([tag, commits]) => {
    const commit = commits.peeled ?? commits.direct;
    return commit === undefined ? [] : [{ tag, commit }];
  });
}

/**
 * The newest stable release. Pre-releases are skipped because "update to latest" should not move a
 * deployment onto a release candidate, and there is no way to opt back out once it has recreated.
 */
export function selectLatestReleaseTag(tags: readonly string[]): string | null {
  let best: ReleaseTag | null = null;
  for (const tag of tags) {
    const parsed = parseReleaseTag(tag);
    if (!parsed || parsed.prerelease !== null) continue;
    if (best === null || compareReleaseTags(parsed, best) > 0) best = parsed;
  }
  return best?.tag ?? null;
}

/** Selects the newest stable release together with the commit-tagged image CI published for it. */
export function selectLatestRelease(releases: readonly RemoteRelease[]): RemoteRelease | null {
  let best: { release: ReleaseTag; commit: string } | null = null;
  for (const candidate of releases) {
    const parsed = parseReleaseTag(candidate.tag);
    if (!parsed || parsed.prerelease !== null) continue;
    if (best === null || compareReleaseTags(parsed, best.release) > 0) {
      best = { release: parsed, commit: candidate.commit };
    }
  }
  return best === null ? null : { tag: best.release.tag, commit: best.commit };
}

export type UpdateStrategy = "pull" | "build";

export interface StrategyDecision {
  strategy: UpdateStrategy;
  reason: string;
}

/**
 * Only the official repository has published images. A fork has to be built where it is deployed,
 * which is minutes rather than seconds, so the choice is stated rather than guessed at call sites.
 */
export function chooseUpdateStrategy(input: { official: boolean }): StrategyDecision {
  if (input.official) {
    return {
      strategy: "pull",
      reason: "Official releases are published as images, so the update is a download and restart.",
    };
  }
  return {
    strategy: "build",
    reason:
      "A fork has no published images, so the server builds this update itself. Expect minutes, not seconds.",
  };
}

export type ExecutionMode = "sidecar" | "checkout" | "unavailable";

export interface ExecutionModeDecision {
  mode: ExecutionMode;
  reason: string | null;
}

/**
 * Which of the two engines can actually apply an update here. The sidecar wins whenever it is
 * configured: a Compose deployment's own container has no `.git` and nothing to restart it, so its
 * only route is the container that outlives it.
 */
export function resolveExecutionMode(input: {
  hasUpdater?: boolean;
  hasCheckout?: boolean;
  disabled?: boolean;
}): ExecutionModeDecision {
  if (input.disabled === true) {
    return { mode: "unavailable", reason: "Self-update is switched off for this deployment." };
  }
  if (input.hasUpdater === true) return { mode: "sidecar", reason: null };
  if (input.hasCheckout === true) return { mode: "checkout", reason: null };
  return {
    mode: "unavailable",
    reason:
      "This deployment has neither an updater sidecar nor a git checkout, so it cannot update itself. Add the `updater` service from infra/compose/docker-compose.prod.yml.",
  };
}

/**
 * What the deployment-owner Settings UI should show. Distinct from {@link resolveExecutionMode}:
 * Compose without the opt-in sidecar is still a Compose install, and source checkouts must never
 * look like they can one-click apply from the API process (no `.git` in the app image; no Docker
 * socket either).
 */
export type InstallKind = "sidecar" | "compose" | "source";

export interface InstallKindDecision {
  kind: InstallKind;
  /** Maps onto ServerUpdateMode for contracts that already use that enum. */
  mode: ExecutionMode;
  reason: string | null;
}

/**
 * `updaterUrlConfigured` means the API was given `RAKAZO_UPDATER_URL` (Compose prod always sets
 * this). Reachability requires both URL and token and a live sidecar. A source checkout is only
 * claimed when there is no Compose updater wiring and `.git` is present on disk.
 */
export function resolveInstallKind(input: {
  updaterUrlConfigured?: boolean;
  updaterReachable?: boolean;
  hasCheckout?: boolean;
  disabled?: boolean;
}): InstallKindDecision {
  if (input.disabled === true) {
    return {
      kind:
        input.updaterUrlConfigured === true
          ? "compose"
          : input.hasCheckout === true
            ? "source"
            : "compose",
      mode: "unavailable",
      reason: "Self-update is switched off for this deployment.",
    };
  }
  if (input.updaterReachable === true) {
    return { kind: "sidecar", mode: "sidecar", reason: null };
  }
  if (input.updaterUrlConfigured === true) {
    return {
      kind: "compose",
      mode: "unavailable",
      reason:
        "The updater sidecar is not reachable. Start the opt-in `updater` profile, or upgrade from the host with the Compose commands below.",
    };
  }
  if (input.hasCheckout === true) {
    return {
      kind: "source",
      mode: "checkout",
      reason: "This is a source checkout. Upgrade from a terminal; Settings cannot apply it.",
    };
  }
  return {
    kind: "compose",
    mode: "unavailable",
    reason:
      "This deployment has no updater sidecar. Upgrade from the host with the Compose commands below, or enable the `updater` profile.",
  };
}

/** Exact host commands from docs/self-host.md for Compose on a published release tag. */
export const COMPOSE_PULL_UPGRADE_COMMANDS = [
  "docker compose --env-file .env -f infra/compose/docker-compose.prod.yml pull api worker web",
  "docker compose --env-file .env -f infra/compose/docker-compose.prod.yml up -d --wait --pull never api worker web",
] as const;

/** Exact host commands from docs/self-host.md for Compose on the default `local` tag. */
export const COMPOSE_LOCAL_BUILD_UPGRADE_COMMANDS = [
  "git pull",
  "GIT_SHA=$(git rev-parse HEAD) docker compose --env-file .env -f infra/compose/docker-compose.prod.yml up -d --wait --pull never --build api worker web",
] as const;

/** @deprecated Prefer {@link COMPOSE_PULL_UPGRADE_COMMANDS}; kept for call-site clarity in tests. */
export const COMPOSE_MANUAL_UPGRADE_COMMANDS = COMPOSE_PULL_UPGRADE_COMMANDS;

/** Exact host commands from docs/self-host.md for source / `pnpm dev` installs. */
export const SOURCE_MANUAL_UPGRADE_COMMANDS = [
  "git pull",
  "pnpm --filter @rakazo/db migrate",
  "# Restart the API and worker processes",
] as const;

/**
 * Host commands Settings should show when the sidecar cannot apply.
 * Compose picks pull vs rebuild from the current image tag when known; otherwise both documented
 * paths from self-host.md so a `local` install is not told to `pull` a tag the registry never serves.
 */
export function manualUpgradeCommands(
  kind: InstallKind,
  options: { imageTag?: string | null } = {},
): readonly string[] {
  if (kind === "source") return SOURCE_MANUAL_UPGRADE_COMMANDS;
  if (kind !== "compose") return [];
  const tag = options.imageTag?.trim() ?? "";
  if (tag !== "" && isLocalImageTag(tag)) return COMPOSE_LOCAL_BUILD_UPGRADE_COMMANDS;
  if (tag !== "" && !isLocalImageTag(tag)) return COMPOSE_PULL_UPGRADE_COMMANDS;
  return [
    "# Published release tag",
    ...COMPOSE_PULL_UPGRADE_COMMANDS,
    "# Local tag (rebuild from checkout)",
    ...COMPOSE_LOCAL_BUILD_UPGRADE_COMMANDS,
  ];
}

export interface ComposeInvocation {
  command: string;
  args: string[];
}

export interface ComposeTarget {
  /**
   * Compose files in overlay order, each passed as its own `--file`. A deployment that layers an
   * overlay on the base file has to be reconciled with the same file list the operator uses, or an
   * update recreates services without the overlay's wiring.
   */
  composeFiles: readonly string[];
  envFiles?: readonly string[];
  /** Passed as `docker compose -p <name>`. Defaults to {@link DEFAULT_COMPOSE_PROJECT_NAME}. */
  projectName?: string;
  /**
   * Services to pull, recreate and roll back. Defaults to {@link RECREATED_SERVICES}. A deployment
   * whose overlay adds an app-image service has to recreate that one too, or the update leaves it
   * running the old code.
   */
  services?: readonly string[];
}

function composeBase(target: ComposeTarget): string[] {
  const projectName = target.projectName ?? DEFAULT_COMPOSE_PROJECT_NAME;
  if (!isValidComposeProjectName(projectName)) {
    throw new Error(`Refusing an unusable Compose project name: ${projectName}`);
  }
  if (target.composeFiles.length === 0) {
    throw new Error("Refusing a Compose target with no Compose file.");
  }
  const args = ["compose", "-p", projectName];
  for (const envFile of target.envFiles ?? []) args.push("--env-file", envFile);
  for (const composeFile of target.composeFiles) args.push("--file", composeFile);
  return args;
}

function targetServices(target: ComposeTarget): readonly string[] {
  const services = target.services ?? [];
  return services.length > 0 ? services : RECREATED_SERVICES;
}

export function composePullArgv(
  target: ComposeTarget,
  services: readonly string[] = targetServices(target),
): ComposeInvocation {
  return { command: "docker", args: [...composeBase(target), "pull", ...services] };
}

export function composeUpArgv(
  target: ComposeTarget,
  options: { build?: boolean; services?: readonly string[] } = {},
): ComposeInvocation {
  const args = [
    ...composeBase(target),
    "up",
    "--detach",
    "--wait",
    "--wait-timeout",
    "300",
    "--pull",
    "never",
  ];
  args.push(options.build === true ? "--build" : "--no-build");
  args.push(...(options.services ?? targetServices(target)));
  return { command: "docker", args };
}

export function composePsArgv(target: ComposeTarget): ComposeInvocation {
  return { command: "docker", args: [...composeBase(target), "ps", "--format", "json"] };
}

/**
 * `git status` as seen inside the Linux sidecar against a Windows checkout. `core.autocrlf=true`
 * makes CR-only worktree noise match what the host already considers clean. The `-c` is argv, not a
 * shell fragment.
 */
export function gitStatusArgv(): string[] {
  return [
    "--no-optional-locks",
    "-c",
    "core.autocrlf=true",
    "status",
    "--porcelain",
    "--untracked-files=no",
  ];
}

/** Worktree vs index, ignoring CR at EOL so a CRLF-only file does not count as dirty. */
export function gitWorktreeContentDiffArgv(): string[] {
  return [
    "--no-optional-locks",
    "-c",
    "core.autocrlf=true",
    "diff",
    "--name-only",
    "--ignore-cr-at-eol",
  ];
}

/** Index vs HEAD, same CR rule, so a staged content change cannot hide behind the worktree check. */
export function gitIndexContentDiffArgv(): string[] {
  return [
    "--no-optional-locks",
    "-c",
    "core.autocrlf=true",
    "diff",
    "--cached",
    "--name-only",
    "--ignore-cr-at-eol",
  ];
}

/** Untracked source can enter `COPY . .`, so a build must not silently include it. */
export function gitUntrackedFilesArgv(): string[] {
  return ["--no-optional-locks", "ls-files", "--others", "--exclude-standard"];
}

export function parseGitNameOnly(stdout: string): string[] {
  const paths: string[] = [];
  for (const line of stdout.split("\n")) {
    const path = line.trim();
    if (path !== "") paths.push(path);
  }
  return paths;
}

export interface TrackedDirtyDecision {
  dirty: boolean;
  dirtyPaths: string[];
}

/**
 * Porcelain lists every tracked path git considers dirty, including CRLF-only noise when a Windows
 * `core.autocrlf=true` checkout is bind-mounted into Linux. `contentChanged` is the same comparison
 * after `--ignore-cr-at-eol`. Porcelain-only paths are dropped; a path that still has a content
 * diff stays dirty. If the content diffs could not be read, porcelain is the last word — the guard
 * is not weakened for a failed filter.
 */
export function resolveTrackedDirtyPaths(input: {
  porcelainChanged: readonly string[];
  contentChanged: readonly string[];
  contentDiffOk: boolean;
  untrackedPaths?: readonly string[];
}): TrackedDirtyDecision {
  const untrackedPaths = input.untrackedPaths ?? [];
  if (!input.contentDiffOk) {
    const dirtyPaths = uniquePaths([...input.porcelainChanged, ...untrackedPaths]);
    return { dirty: dirtyPaths.length > 0, dirtyPaths };
  }
  const dirtyPaths = uniquePaths([...input.contentChanged, ...untrackedPaths]);
  return { dirty: dirtyPaths.length > 0, dirtyPaths };
}

function uniquePaths(paths: readonly string[]): string[] {
  const seen = new Set<string>();
  const unique: string[] = [];
  for (const path of paths) {
    if (path === "" || seen.has(path)) continue;
    seen.add(path);
    unique.push(path);
  }
  return unique;
}

export interface ComposeUpdateStep {
  id: string;
  label: string;
  command: string;
  args: string[];
}

export interface ComposeUpdatePlanInput {
  strategy: UpdateStrategy;
  target: ComposeTarget;
  /** Only the build path touches the checkout, and only when the remote has to be re-pointed. */
  repoUrl?: string;
  branch?: string;
  repointRemote?: boolean;
  remote?: string;
}

/**
 * Ordered work for one Compose update.
 *
 * Migrations are absent on purpose. The `api` service runs `prisma migrate deploy` as the first
 * thing in its own start command, so a recreate already orders them correctly: Compose stops the
 * old container, the new one migrates with the new code, then serves. Running migrations from here
 * would instead apply the new schema while the old process is still answering requests, which is
 * the window this ordering exists to close.
 */
export function composeUpdatePlan(input: ComposeUpdatePlanInput): ComposeUpdateStep[] {
  const steps: ComposeUpdateStep[] = [];
  if (input.strategy === "build") {
    const remote = input.remote ?? DEFAULT_UPDATE_REMOTE;
    const branch = input.branch ?? "main";
    if (input.repointRemote === true && input.repoUrl) {
      steps.push({
        id: "remote",
        label: "Point the checkout at the chosen repository",
        command: "git",
        args: ["remote", "set-url", remote, input.repoUrl],
      });
    }
    steps.push(
      {
        id: "fetch",
        label: "Fetch the latest commits",
        command: "git",
        args: ["fetch", remote, branch],
      },
      {
        id: "checkout",
        label: `Check out ${branch}`,
        command: "git",
        args: ["checkout", branch],
      },
      {
        id: "merge",
        label: "Fast-forward to the fetched commit",
        command: "git",
        args: ["merge", "--ff-only", `${remote}/${branch}`],
      },
    );
    const up = composeUpArgv(input.target, { build: true });
    steps.push({
      id: "recreate",
      label: "Build the new images and recreate the services",
      command: up.command,
      args: up.args,
    });
    return steps;
  }

  const pull = composePullArgv(input.target);
  const up = composeUpArgv(input.target);
  steps.push(
    { id: "pull", label: "Download the new images", command: pull.command, args: pull.args },
    { id: "recreate", label: "Recreate the services", command: up.command, args: up.args },
  );
  return steps;
}

export type RollbackDecision = { tag: string } | { error: string };

/**
 * Rollback is "deploy the tag that was running before the last update". The updater reuses the
 * image already cached on this host instead of trusting that a mutable registry tag still points
 * at the same content.
 */
export function rollbackTarget(input: {
  currentTag: string | null;
  previousTag: string | null;
}): RollbackDecision {
  if (!input.previousTag) {
    return { error: "No previous image tag was recorded, so there is nothing to roll back to." };
  }
  if (!isValidImageTag(input.previousTag)) {
    return { error: "The recorded previous image tag is not a usable tag." };
  }
  if (input.previousTag === input.currentTag) {
    return { error: "The previous image tag is the one already running." };
  }
  return { tag: input.previousTag };
}

/**
 * Rewrites managed assignments in the deployment's `.env` without disturbing anything else in it,
 * so the operator's own `docker compose --env-file .env … up -d` keeps using the pinned tag.
 * Values are checked against a conservative grammar first: this file is read by Compose as
 * interpolation input, and it is the last place a repository URL or ref could leak into a build
 * argument or a service definition.
 */
export function upsertEnvAssignments(
  contents: string,
  assignments: Readonly<Record<string, string>>,
): string {
  for (const [key, value] of Object.entries(assignments)) {
    if (!ENV_KEY.test(key)) throw new Error(`Refusing to write the env key ${key}.`);
    if (!ENV_VALUE.test(value)) throw new Error(`Refusing to write the value of ${key}.`);
  }
  const newline = contents.includes("\r\n") ? "\r\n" : "\n";
  const lines = contents.split(/\r?\n/);
  const pending = new Map(Object.entries(assignments));
  const next = lines.map((line) => {
    const key = line.match(/^([A-Z][A-Z0-9_]*)=/)?.[1];
    if (key === undefined || !Object.hasOwn(assignments, key)) return line;
    const value = assignments[key] as string;
    pending.delete(key);
    return `${key}=${value}`;
  });
  if (pending.size > 0) {
    while (next.length > 0 && next[next.length - 1] === "") next.pop();
    if (next.length > 0) next.push("");
    for (const [key, value] of pending) next.push(`${key}=${value}`);
  }
  const rendered = next.join(newline);
  return rendered.endsWith(newline) ? rendered : `${rendered}${newline}`;
}

export interface UpdateRequest {
  repoUrl: string;
  branch: string;
  official: boolean;
}

export type UpdateRequestResult = { request: UpdateRequest } | { error: string };

/**
 * The sidecar's own front door. It holds the Docker socket, so it is a separate trust boundary and
 * re-runs every check the API already ran rather than trusting that the caller sanitized anything.
 */
export function validateUpdateRequest(input: {
  repoUrl?: unknown;
  branch?: unknown;
}): UpdateRequestResult {
  if (typeof input.repoUrl !== "string") return { error: "A repository URL is required." };
  if (typeof input.branch !== "string") return { error: "A branch is required." };
  const url = normalizeRepoUrl(input.repoUrl);
  if ("error" in url) return { error: url.error };
  const branch = normalizeUpdateBranch(input.branch);
  if ("error" in branch) return { error: branch.error };
  return {
    request: { repoUrl: url.url, branch: branch.branch, official: isOfficialRepoUrl(url.url) },
  };
}